1. Technical Field
The present invention relates to a gas cell, a quantum interference device, an atomic oscillator, an electronic device, and a moving object.
2. Related Art
An atomic oscillator which oscillates on the basis of energy transition of atoms of an alkali metal such as rubidium or cesium is known as an oscillator having excellent long-term frequency stability.
In general, an operation principle of the atomic oscillator is mainly classified into a method that uses a double resonance phenomenon of light and microwaves and a method that uses a quantum interference effect (coherent population trapping (CPT)) of two types of light having different frequencies.
In a typical atomic oscillator, the alkali metal is sealed in a gas cell along with a buffer gas (for example, see JP-A-2010-245805). For example, in JP-A-2010-245805, in a case of using a gas mixture of nitrogen and argon as the buffer gas, the relationship between the mixing ratio and the temperature coefficient (temperature characteristics) of the gas mixture is described.
Recently, due to the demand for a reduction in the size of the atomic oscillator, a reduction in the size of the gas cell is desired.
However, in a case where the gas cell is reduced in size, even when the mixing ratio of the gas mixture during the use of the gas mixture of nitrogen and argon as the buffer gas is adjusted by using the relationship described in JP-A-2010-245805, there is a problem that temperature characteristics cannot be improved. It is inferred that this is because the relationship between the mixing ratio and the temperature characteristics is changed according to the size of the gas cell.